Improvements in artificial muscle actuators

ABSTRACT

A hinge-type actuator device in accordance with the present disclosure may include a first and second paddle, a first and second artificial muscle actuator segment, and a plurality of contacts, where the first and second artificial muscle actuator segments are actuated via the contacts, actuation of the first artificial muscle actuator segment causes the first and second paddle to open the hinge-type actuator, and actuation of the second artificial muscle actuator segment causes the first and second paddle to close the hinge-type actuator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority, pursuant to 35 U.S.C. § 119(e) to U.S.Provisional Application 62/431,717 filed on Dec. 8, 2016, and U.S.Provisional Application 62/462,544 filed on Feb. 23, 2017, and which areincorporated by reference in their entireties.

BACKGROUND OF INVENTION

Thermally driven torsional actuators based on twisted polymeric andcarbon nanotube (CNT) fibers and yarns have a wide range ofapplications. Artificial muscle actuators comprising twisted and/orcoiled polymers have the advantage of low cost, high production volume,and design simplicity. Artificial muscle actuators may have advantagesover small motors because of the greatly simplified engineering andlower product costs.

SUMMARY

In one aspect, a hinge-type actuator device in accordance with thepresent disclosure may include a first and second paddle, a first andsecond artificial muscle actuator segment, and a plurality of contacts,wherein the first and second artificial muscle actuator segments areactuated via the contacts, actuation of the first artificial muscleactuator segment causes the first and second paddle to open thehinge-type actuator, and actuation of the second artificial muscleactuator segment causes the first and second paddle to close thehinge-type actuator.

In another aspect, a linear displacement device in accordance with thepresent disclosure may include at least one artificial muscle actuator,an arm attached to the at least one artificial muscle, a body that isrestricted to move along a line, and a stationary channel that restrictsthe motion of the body to linear motion, wherein the at least oneartificial muscle actuator causes the body to move along the line,wherein the body is further restricted to move along a surface of thearm, wherein the at least one artificial muscle actuator is a rotationalmuscle actuator, and wherein the arm rotates in concert with the atleast one artificial muscle actuator.

In another aspect, a linear displacement device in accordance with thepresent disclosure may include at least one artificial muscle actuator,and a body that is restricted to move along a line, wherein the at leastone artificial muscle actuator causes the body to move along the line,wherein one of the at least one artificial muscle actuators expands whenactuated, wherein one of the at least one artificial muscle actuatorscontracts when actuated, and wherein a first end of each of theartificial muscle actuators is attached to a base and a second end ofeach of the artificial muscle actuators is attached to the body.

In another aspect, a mechanical accumulator in accordance with thepresent disclosure may include at least one rotational artificialmuscle, an arm attached to the at least one artificial muscle, and alatching mechanism that maintains an initial position of the mechanicalunless a predetermined amount of force is applied by the at least onerotational artificial muscle, wherein the arm rotates in concert withthe at least one rotational artificial muscle actuator.

Other aspects and advantages of the claimed subject matter will beapparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

Certain embodiments of the disclosure will hereafter be described withreference to the accompanying drawings, where like reference numeralsdenote like elements. It should be understood, however, that theaccompanying figures illustrate the various implementations describedherein and are not meant to limit the scope of various technologiesdescribed herein.

FIG. 1 is a schematic of a hinge-type actuator in accordance with one ormore embodiments disclosed herein.

FIG. 2 is another schematic of a hinge-type actuator in accordance withone or more embodiments disclosed herein.

FIG. 3 is a schematic of a linear displacement device comprising arotational artificial muscle actuator in accordance with one or moreembodiments disclosed herein.

FIG. 4 is a schematic of a linear displacement device comprising alinear artificial muscle actuator in accordance with one or moreembodiments disclosed herein.

FIG. 5 is a schematic of a linear displacement device as a pistonmodules comprising linear artificial muscle actuators in accordance withone or more embodiments disclosed herein. FIG. 5 has plan and sideviews.

FIG. 6 is a schematic of a linear displacement device in accordance withone or more embodiments disclosed herein.

FIG. 7 is a schematic of a mechanical accumulator, or catapult, inaccordance with one or more embodiments disclosed herein.

DETAILED DESCRIPTION

In the following detailed description of embodiments of the invention,numerous specific details are set forth in order to provide a morethorough understanding of the invention. However, it will be apparent toone of ordinary skill in the art that the invention may be practicedwithout these specific details. In other instances, well-known featureshave not been described in detail to avoid unnecessarily complicatingthe description.

Embodiments of the present disclosure will now be described in detailwith reference to the accompanying figures. Like elements in the variousfigures may be denoted by like reference numerals for consistency.Further, it will be apparent to one of ordinary skill in the art thatthe embodiments disclosed herein may be practiced without the specificdetails provided to allow a more thorough understanding of the claimedsubject matter. Further still, one of ordinary skill in the art willreadily recognize that the scale of the elements in the accompanyingfigures may vary without departing from the scope of the presentdisclosure.

The term “or” is understood to be an “inclusive or” unless explicitlystated otherwise. Under the definition of “inclusive or,” the expression“A or B” is understood to mean “A alone, B alone, or both A and B.”Similarly, “A, B, or C” is understood to mean “A alone, B alone, Calone, both A and B, both A and C, both B and C, or A and B and C.”

The artificial muscle actuators may be comprised of any type ofartificial muscle. Artificial muscle materials may include polymers,carbon nanotubes (CNTs), or any other suitable material. In one or moreembodiments, a nylon fiber may be twisted into a coiled shape with smallcopper wire wound around the nylon to provide electrical conductivity.Nylon is relatively abundant and inexpensive. Other materials may bedesired for their greater actuation speeds, temperatures, durability,precision, or other useful property.

In accordance with embodiments disclosed herein, a carbon nanotubeactuator comprised of a plurality of carbon nanotube (CNT) sheetsstacked on top of each other may be used. In one or more embodiments,the plurality of CNT sheets may comprise a single sheet wrapped over onitself multiple times. Such CNT sheets may be considered isotropic inaccordance with embodiments disclosed herein. In one or moreembodiments, these CNT sheets, when stacked on top of each other, becomeessentially inseparable and cannot be unwrapped. CNT layers in somecases may contain 50 CNT sheets, 100 CNT sheets, or more.

Muscle actuators may be activated with application of heat supplied byapplying a voltage across the material. Other possibilities includechemical reaction based artificial muscle actuators and heat-activatedmuscle actuators heated through means other than an applied voltage.Other heating means include induction heating, magnetic hysteresis, thedirect application of heat and the like. Still other possibilities areabsorption-activated and photonically-activated artificial muscleactuators.

An artificial muscle may also be referred to as a sheet muscle, a hybridnanofiber artificial muscle, a hybrid muscle, a hybrid actuator, anartificial muscle actuator, or the like.

The term hybrid is used to indicate that CNT sheets are infiltrated witha guest actuation material to form one or more CNT layers, and furtherthat the CNT layers may include other materials as well. For example,materials may include elastomers (e.g., silicone-based rubber,polyurethane, styrene-butadiene copolymer, natural rubber, and thelike), fluorinated plastics (e.g., perfluoroalkoxy alkane (PFA),polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP),and the like), aramids, (e.g., Kevlar, nomex, and the like), epoxies,polyimides, paraffin wax, and the like.

In embodiments disclosed herein, a yarn is a long, continuous length ofone or more fibers. In a CNT yarn, the fibers are CNTs, and a core fibermay be the fiber around which CNT layers are wrapped.

In general, embodiments of the invention relate to advancements inmuscle fiber actuator technologies. For example, one or more embodimentsof the present disclosure relate to artificial muscle actuators. One ormore embodiments include a hinge-type actuator. One or more embodimentsinclude a linear displacement, or button-type, actuator. One or moreembodiments include a mechanical accumulator, or catapult-type,actuator. One of ordinary skill in the art will appreciate that theembodiments disclosed herein may be used in combination with otherembodiments, or incorporated into other existing actuator technologies,such as those incorporated by reference above.

Embodiments of the invention include actuator materials, or artificialmuscles, including twist-spun nanofiber yarn and twisted polymer fibersthat generate torsional and/or tensile actuation when poweredelectrically, photonically, thermally, chemically, by absorption, or byother means. Embodiments of the invention include actuators that utilizecoiled yarns or polymer fibers and may be either neat or include aguest.

In one or more embodiments, an artificial muscle actuator may functionas a hinge-type structure.

FIG. 1 is a schematic of a hinge-type actuator in accordance with one ormore embodiments disclosed herein. In FIG. 1, two artificial muscleactuators 106, 108 are arranged parallel to each other and designed torotationally actuate in opposite directions. FIG. 1 also includeselectrical and/or physical contacts 110, 112, 114, 116, 118, 120 betweenthe artificial muscle actuators 106, 108 and the paddles 122, 124. Thus,in one or more embodiments, electrical connections may serve asmechanical connections from the paddles to the artificial muscleactuators. In these embodiments, the artificial muscle actuators 106,108 are not rigidly held in a diagonal position, but rather areflexible. Also, each artificial muscle actuator 106, 108 is connected toboth paddles 122, 124, which is necessary to facilitate the desiredmotion. Further, when one of artificial muscle actuators 106, 108 isactivated to close the hinge, the hinge may close without the artificialmuscle actuators 106, 108 colliding with each other and hindering themotion.

In these embodiments, the contacts 110, 112, 114, 116, 118, 120 may beelectrical, and addition physical contacts may be provided between theartificial muscle actuators 106, 108 and the paddles 122, 124. In thiscontext, physical contacts physically connect the paddles to theartificial muscle actuators such that actuation moves the paddles.Electrical contacts enable current to be applied to the artificialmuscle actuators for actuation.

For example, referring to FIG. 1, an electrical current may pass throughthe contact 110 through the artificial muscle actuator 106 to the othercontacts 114, 118. The electrical current will heat up the artificialmuscle actuator and activate it, causing the paddles 122, 124 to cometogether. Similarly, an electrical current supplied through the contact112 to the contacts 116, 120 will cause actuation in the artificialmuscle actuator 108, which in turn causes the paddles 122, 124 toseparate. Each artificial muscle actuator 106, 108, may thus be operatedindependently of the other and may be operated as a bi-stable system.

In the embodiments of FIG. 1, the artificial muscle fibers 106, 108 arebound together on each paddle 122, 124. The connectors 114, 116 (andconnectors 118, 120) may be electrically connected to each other and mayserve as grounding connections, as well as physical connections betweenthe artificial muscle fibers 106, 108 and paddles 122, 124.

FIG. 2 is a schematic of another hinge-type actuator in accordance withone or more embodiments disclosed herein. The embodiments illustrated inFIG. 2 include two artificial muscle actuators 206, 208 linearly alignedand configured to actuate in opposite directions. FIG. 2 also includeselectrical and/or physical contacts 210, 212, 214, 216 as in theembodiments described with reference to FIG. 1. The linear actuators206, 208 may be constructed from a single artificial muscle fiber, withthe electrical contacts defining the difference between the artificialmuscle actuator 206 and the artificial muscle actuator 208. Two of thecontacts 212, 216 are located at the junction of the two artificialmuscle actuators 206, 208, while contacts 210, 214 are located at endsof each of the artificial muscle actuators 206, 208, respectively.

In these embodiments, an electrical current may pass through the contact210 through the artificial muscle actuator 206 to the other contact 212.The electrical current will heat up the artificial muscle actuator 206and activate it, causing the paddles 218, 220 to come together.Similarly, an electrical current supplied through the contact 214, 216will cause actuation in the artificial muscle actuator 208, causing thepaddles 218, 220 to separate.

The embodiments described in FIG. 2 may be more compact than those ofFIG. 1. However, the embodiments of FIG. 1 may provide more torqueduring actuation. One of ordinary skill in the art will appreciate thatthe configuration may be selected or modified depending on the specificapplication.

The embodiments disclosed above and in FIGS. 1 and 2 may be used for anyhinge-type actuation. For example, self-opening and closing hatches,doors, laptops, lids, books, origami, and the like. For example, apossible device may be a simple box that can be configured toautomatically unfold and refold with the application of electriccurrent. The configurations presented herein would be resistant toactuating with changes in ambient temperature because the two muscleactuators would oppose each other's movement.

Embodiments disclosed herein also include smooth reversal of actuation.For example, one or more embodiments of artificial muscle actuatordevice may be configured to rotate a paddle in an arc, reverse directionand then rotate in the opposite direction. In some applications, ifsensitive devices are mounted onto the paddle, it may be desirable thata stop of the actuation and a reversal of direction be made as smoothlyas possible. In these embodiments, the applied currents are decreasedslowly for a few steps, stopped, and then ramped up in the reversedirection equally slowly. As such, for example, the actuation of apaddle with a mounted device may come to a smooth stop and reversedirection with no jerking behavior.

In one or more embodiments, an artificial muscle actuator may be alinear displacement, or button-type, device. In one or more embodiments,a linear displacement device may exhibit spring-like behavior, but yetcan still be controlled electrically. The artificial muscle actuatorssuspending the linear displacement device are capable of providing theelastic ability similar to a spring, while still being controllableusing electronics. If spring-like motion is not desired, then the lineardisplacement device may be configured to have one or more latchingmechanisms, for example, mechanical or magnetic latches, that hold thelinear displacement device in position. The latching mechanisms may bedesired to prevent the linear displacement device from moving slightly.A predetermined amount of force may then be required to displace thelinear displacement device from a latched position. The spring-likebehavior of the artificial muscle actuators would return the lineardisplacement device to the stable latched position when the externalforce is removed. In one or more embodiments, there may be two or morestable positions for the artificial muscle actuators with latchingmechanisms. The artificial muscle actuators may also be electricallyactivated to displace the displacement device into or out of one or moreof these stable positions.

The latching mechanisms may be utilized fully with either linear orrotational artificial muscle actuators and may be combined with the useof bi-stable artificial muscle actuators if desired. A bi-stableartificial muscle actuator is one which may not require a continuoussupply of energy to remain actuated. A bi-stable artificial muscleactuator can maintain its position without the need for externallatches, gears, magnets or the constant application of current toproduce heat. Bi-stable artificial muscle actuators may be used incombination with the latches, gears and magnets, to produce a morerobust design.

In one or more embodiments, a linear displacement device providinglinear displacement comprises a rotational artificial muscle actuator. Arotational artificial muscle actuator, also referred to as a torsionalartificial muscle actuator, is one that twists (or untwists) uponactuation. These rotational artificial muscle actuators may have anattached piece, or arm, that converts the rotational motion of theartificial muscle actuators into linear motion for a body.

Among the advantages of the linear displacement device are the low costof materials, a simple design, and the ability to replace springs with adevice that allows for control and does not require the device to returnto a specific position when not activated. In addition, the lineardisplacement device may be actively or passively thermally controlled.An example of passive thermal control may be actuation based on ambienttemperature. Active control may include activation of the artificialmuscle actuator using electrical current. Further, the materialscomprising the linear displacement device may be selected to providenecessary resistance to heat, corrosion, and the like.

As shown in FIG. 3, in one or more embodiments, the linear displacementdevice 300 may comprise at least one artificial muscle actuator 306(shown in end view) designed to rotate with application of heat. Theheat may be provided by passive or active thermal control. Passivethermal control may be a direct response to the ambient temperature. Inone or more embodiments, active thermal control is provided throughelectrical current passing through a wire (not shown) wound around theartificial muscle fiber. Attached to the artificial muscle actuator is ameans to convert the rotational motion of the muscle actuator into thelinear motion of the linear displacement device. The means may include agear system attached to the artificial muscle actuator 306. This maycomprise a simple arm 330 attached to the artificial muscle actuator. Inone or more embodiments, the arm 330 may be a straight piece. The arm330 may be attached at or near the midpoint of the length of theartificial muscle actuator 306. When the artificial muscle actuator 306is rotated, the arm 330 rotates with it. In other words, the arm 330rotates in concert with the rotational artificial muscle actuator 306. Abody 334 may be positioned on the surface of the arm 330.

In one or more embodiments, the arm 330 includes a channel 332 in whichbody 334 may be constrained to move. Further, a stationary channel 346may also be provided to constrain, or restrict, the motion of body 334to be linear along the direction of stationary channel 346. In one ormore embodiments, stationary channel 346 may be simply another surfacewhile another force, for example gravity, provides a constraint to keepbody 334 in contact with stationary channel 346.

When the rotational artificial muscle actuator 306 is rotated the arm330 will exert a rotational force on the body 334. Either the connectionbetween the body 334 and the arm 330 or the body 334 itself should beconfigured so that the body 334 may be displaced only in a lineardirection.

In one or more embodiments, a rack and pinion system may be used totranslate rotational motion into linear displacement.

In one or more embodiments, the linear displacement device 300 comprisestwo artificial muscle actuators, each having an arm operating so thatboth artificial muscle actuators produce linear displacementsimultaneously. In one or more embodiments, the linear displacementdevice may comprise more than two artificial muscle actuators.

The linear displacement device may further be configured to have alatching mechanism to firmly maintain the linear displacement device ina particular position. Latching mechanisms may be mechanical, magnetic,or any other suitable method for fixing the position of the lineardisplacement device.

In one or more embodiments, the arms may be designed to open and closevalves, in a gate fashion. In one or more embodiments, the arm describedabove may comprise a paddle. Two or more artificial muscle actuatorswith said paddles attached may then be configured so that their paddlesmeet precisely, sealing a valve. With the application of heat, eitherpassively or actively, the artificial muscle actuators may rotate andopen the valves. The valves may be configured to open in the samedirection, or they may each open in opposite directions. They may alsobe configured to operate independently of each other. Furthermore, theartificial muscle actuators with paddles attached may be laid out end toend, so a large span may be controlled by many of these artificialmuscle actuators. This approach may provide for better control overfluid flow in a pipe, tube, or similar object, with many small aperturesopening rather than a few large apertures. This arrangement ofartificial muscle actuators with paddles may prevent non-uniform fluidflow.

As shown in FIG. 4, in one or more embodiments, linear actuating muscleactuators 406, 408 may be used in a linear displacement device 400. Inone or more embodiments using linear actuating muscle actuators, onehomochiral 406 and one heterochiral 408 muscle actuator may be placeddirectly beside each other. A homochiral muscle actuator 406 is one thatcontracts linearly when heated, the direction of twist being the same asthe direction of coiling. In contrast, a heterochiral muscle actuator408 expands linearly when heated; the direction of twist being theopposite from the direction of coiling.

The linear displacement device 400 may be used to expose a body 434 froman otherwise flush surface. Similarly, the linear displacement device400 may be used to hide a body 434 that extends from a flush surface.Upon the application of force the body 434 will return to its positionlike a spring, yet can still be controlled as if connected to a motor.In one or more embodiments, a linear displacement device may be used asa camera lens extender, a Braille e-reader, texture control (e.g., anarray of pins), changing surface roughness, and automatic suction cups.

To move this linear displacement device 400 from the down position intothe up position, the heterochiral muscle actuator 408 is activatedcausing the muscle actuator 408 to expand, pushing the lineardisplacement device 400 to the extended position. In one or moreembodiments, a latching mechanism 448 is used to maintain the positionof the linear displacement device 400 in the extended state. In order toretract the linear displacement device 400 into its retracted state thehomochiral muscle actuator 406 is activated, which contracts and pullsthe linear displacement device 400 into its retracted state.

In one or more embodiments, the homochiral muscle actuator 406 may bereplaced by any actuator which retracts lengthwise. The heterochiralmuscle actuator 408 may also be replaced by any actuator which extendslengthwise.

As shown in FIG. 5, in one or more embodiments, a linear displacementdevice may be used as a piston module 500. The module 500 may comprise apiston 550 in a housing 554. The housing face opposite the piston 550may comprise a copper ground 552 for artificial muscle actuators 506,507, and 508. Artificial muscle actuators 506, 507, 508 may attach atone end to the housing at the copper ground and to the piston at theother end. In one or more embodiments, the piston module 500 comprisesat least one puller artificial muscle actuator 506, 507. The pullerartificial muscle actuator 506, 507 may be used to pull piston 550toward the copper ground 552. The puller artificial muscle actuator 506,507 may be a homochiral muscle actuator. The piston module 500 may alsocomprise a pusher artificial muscle actuator 508. The pusher artificialmuscle actuator 508 may be used to push the piston 550 away from thecopper ground 552. The pusher artificial muscle actuator 508 may be aheterochiral muscle actuator. The artificial muscle actuators 506, 507,508 may be actuated individually or in various combinations. Actuationmay be by electrical current or by other actuation means as disclosedherein. In one or more embodiments, piston module 500 may comprise ahigh-temperature material for non-actuator and non-metallic parts. Thismaterial may be, for example, Teflon.

As shown in FIG. 6, in one or more embodiments, a single linearactuating muscle actuator may be used in a linear displacement device600. A pin 668 may be secured into the center of the artificial muscleactuator 606. The actuating muscle actuator 606 may be considereddivided into two segments by the pin 668. One end of the first segment670 may be attached to the center pin. The other end of the firstsegment may be attached to the body 634 that one desires to displace.The first segment 670 may be activated by passing electric currentthrough it. The electric current may cause the artificial muscleactuator 606 to expand, lifting the body 634 into its extended state. Aside effect is that the second segment 672 will up-twist and contract.Up-twist means that the fiber in the coiled segment being compressed isreceiving twist from the coil. Up-twist may be the result of compressinga homochiral coil. Once the body 634 has reached its desired extendedposition, then it may be held there by latches or other latchingmechanisms 648.

To retract the body 634 into its retracted state the second artificialmuscle actuator segment 672 is activated causing it to extend andup-twist the first segment 670. The up-twisting causes the first segment670 to contract forcing the body 634 into the retracted position.

The linear displacement device may be made to operate in many ways. Theartificial muscle actuators, in any configuration, may be used to placethe linear displacement device in the extended position. An electriccurrent may be used to heat and actuate the muscle actuators causinglinear motion of the body. The device may then have a series of latchesor magnets which hold the device in the extended position withoutrequiring that the artificial muscle actuators be continuously heated.Upon the application of sufficient external force, the latchingmechanism may be overcome and the linear displacement device may bepositioned in its retracted position. If desirable the device may bemaintained in its retracted position using a latching mechanism orthrough muscle actuation. Alternatively, the linear displacement devicemay be configured to return the device to its extended position throughmuscle actuation.

In one or more embodiments, the artificial muscle actuator may beoperated bi-stable mode so that it automatically returns to the extendedposition. In this case the latching mechanism on the extended positioncan be used to simply prevent small oscillations in the muscle actuatorand to provide a threshold amount of force necessary to cause the lineardisplacement device to displace. In this way the artificial muscleactuator may passively act as a spring, returning the lineardisplacement device to its original state and can be actively actuated.

In one or more embodiments, the artificial muscle actuators may bedesigned to operate as bi-stable polymer actuators. This would enablethe artificial muscle actuators to maintain their position without theneed for external latches, gears, magnets or the constant application ofcurrent to produce heat. In one or more embodiments, the bi-stableartificial muscle actuators may be used in combination with the latches,gears, and magnets, to produce a more robust design.

As shown in FIG. 7, one or more embodiments of the invention aredirected to a mechanical accumulator 700, or catapult, that utilizes anartificial muscle actuator 706. In one or more embodiments, theartificial muscle actuator 706 may comprise a plurality of artificialmuscle actuators 706, 708.

In these embodiments, an artificial muscle actuator 706, 708 may be usedin conjunction with a latching mechanism 748. The latching mechanism 748is designed to prevent the artificial muscle actuator 706, 708 fromcausing movement when the artificial muscle actuator is first activated.Possible latching mechanisms include magnets, mechanical latches, andother artificial muscle actuators among others. Any means to hold themuscle actuators at a particular position, until the muscle actuator cangenerate sufficient force to break free of the latching mechanism may beused. Another artificial muscle actuator can be used as latchingmechanism 748 to hold the position of artificial muscle actuator 706,708 while torque is generated in accordance with embodiments disclosedherein. The latching mechanism artificial muscle actuator may be causedto release allowing the torque generating artificial muscle actuator706, 708 to overcome it and rapidly actuate.

An advantage of using an artificial muscle actuator as a latchingmechanism is it allows for user control over the exact tension requiredto actuate to be done by using software at the local level. Thus, thepredetermined amount of force required to overcome the latchingmechanism artificial muscle actuator may be varied by a user. A singleproduct may be produced with the user programming the lineardisplacement device to release at specific tension. An actuating meanscauses the artificial muscle actuator, or fiber, to initially accumulateenergy. When the accumulated energy is sufficient to overcome thelatching mechanism 748, the latching mechanism suddenly releasesresulting in a forceful actuation. In one or more embodiments, a bundleof artificial muscle fibers may be used because of the increased torqueproduced by a bundle of artificial muscle fibers in comparison to asingle artificial muscle actuator of comparable dimensions. However,embodiments disclosed herein are not limited as such.

Examples of the actuating means include, but are not limited to, aheater, or electrically applying heat to the artificial muscle fibers.Examples of the latching mechanism 748 include, but are not limited to,magnets, mechanical latches, other artificial muscle actuators, orcombinations thereof.

Any means to hold the artificial muscle fibers in a particular position,until the muscle actuator can generate sufficient force to break free ofthe latching mechanism may be used. For example, another artificialmuscle actuator may be used to hold the position of another actuatorwhile it generates torque. In these embodiments, the holding artificialmuscle actuator may be actuated to release.

In one or more embodiments of the mechanical accumulator 700, themechanical accumulator may include multiple latching mechanisms to granta multitude of stable positions. For example, an artificial muscleactuator may have two stable positions to function as a valve designedto be either completely closed or completely open. In such embodiments,the artificial muscle actuator may be initially activated to generatetorque and, when the latching mechanism is deactivated, the artificialmuscle actuator will release and quickly transfer into another stableposition. The rapid application of force in these embodiments may bebeneficial to overcoming any resistance in such a valve, for example bya fluid flowing through the valve. The rapid application of force mayalso prevent the valve from being in an intermediate state between openand closed.

Electrical current is used to heat the artificial muscle actuator,either an individual fiber or a plurality of fibers in a bundle, whichis held steady by a latching mechanism. While the muscle actuators arebeing heated, they generate internal stresses which would normally berelieved by the rotational motion of the artificial muscle actuators,but the latching mechanism prevents rotation, forcing the energy toaccumulate within the muscle actuator. When the internal tension issufficiently strong, it will overcome the resistance of the latchingmechanism and the muscle actuator will actuate rapidly and forcefully.

As always with artificial muscle actuators, they may be actively poweredusing electrical current or they may be passively powered fromenvironmental temperature conditions.

Further, without having the benefit of a latching mechanism toaccumulate tension, a similar rapid actuation may be achieved. A largecurrent applied very quickly to a thick artificial muscle actuator mayto generate rapid actuation. Such large currents applied so quicklyrequire a capacitor and conductors which can withstand said largecurrents. Both the capacitor and the more durable conductor, for examplea thicker gauge wire, may increase manufacturing complexity and cost.

The mechanical accumulator may effectively diminish the need for largecurrents applied quickly and prevent the commensurate strain onsupporting electrical systems and the artificial muscle actuator itself.

Although the disclosure has been described with respect to only alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that various other embodiments maybe devised without departing from the scope of the present invention.Accordingly, the scope of the invention should be limited only by theattached claims.

What is claimed is:
 1. A hinge-type actuator device comprising: a firstand second paddle; a first and second artificial muscle actuatorsegment; and a plurality of contacts, wherein the first and secondartificial muscle actuator segments are actuated via the contacts,actuation of the first artificial muscle actuator segment causes thefirst and second paddle to open the hinge-type actuator, and actuationof the second artificial muscle actuator segment causes the first andsecond paddle to close the hinge-type actuator.
 2. The hinge-typeactuator of claim 1, wherein the first and second artificial muscleactuator segments are arranged parallel to each other.
 3. The hinge-typeactuator of claim 1, wherein the first and second artificial muscleactuator segments are arranged linearly.
 4. The hinge-type actuator ofclaim 1, wherein the plurality of contacts are electrical.
 5. Thehinge-type actuator of claim 1, wherein the plurality of contacts arephysical.
 6. The hinge-type actuator of claim 1, wherein the pluralityof contacts are both electrical and physical.
 7. A linear displacementdevice comprising: at least one artificial muscle actuator; an armattached to the at least one artificial muscle; a body that isrestricted to move along a line; and a stationary channel that restrictsthe motion of the body to linear motion, wherein the at least oneartificial muscle actuator causes the body to move along the line,wherein the body is further restricted to move along a surface of thearm, wherein the at least one artificial muscle actuator is a rotationalmuscle actuator, and wherein the arm rotates in concert with the atleast one artificial muscle actuator.
 8. A valve comprising at least onelinear displacement device of claim 7, wherein the arm of the at leastone linear displacement device is a paddle that forms a valve gate.
 9. Avalve comprising a plurality of linear displacement devices of claim 7,wherein the arms of the plurality of linear displacement devices arepaddles, and wherein the paddles form a valve gate.
 10. A lineardisplacement device comprising: at least one artificial muscle actuator;and a body that is restricted to move along a line; wherein the at leastone artificial muscle actuator causes the body to move along the line,wherein one of the at least one artificial muscle actuators expands whenactuated, wherein one of the at least one artificial muscle actuatorscontracts when actuated, and wherein a first end of each of theartificial muscle actuators is attached to a base and a second end ofeach of the artificial muscle actuators is attached to the body.
 11. Thelinear displacement device of claim 10, further comprising: a latchingmechanism that maintains a position of the linear displacement deviceunless a predetermined amount of force is applied by the at least oneartificial muscle actuator.
 12. The linear displacement device of claim11, wherein the latching mechanism comprises a second artificial muscleactuator that allows for user control of the predetermined amount offorce required to release the latching mechanism.
 13. The lineardisplacement device of claim 10, wherein: the artificial muscle actuatorthat expands when actuated is a heterochiral artificial muscle actuator,and the artificial muscle actuator that contracts when actuated is ahomochiral artificial muscle actuator.
 14. A mechanical accumulatorcomprising: at least one rotational artificial muscle; an arm attachedto the at least one artificial muscle; and a latching mechanism thatmaintains an initial position of the mechanical unless a predeterminedamount of force is applied by the at least one rotational artificialmuscle, wherein the arm rotates in concert with the at least onerotational artificial muscle actuator.
 15. The mechanical accumulator ofclaim 14, wherein the latching mechanism is a second artificial muscleactuator that allows for user control of the predetermined amount offorce required to release the latching mechanism.